Optical pulse shaping methods can be used to adjust the properties of ultrafast optical pulses. For example, in an optical pulse shaper, the amplitude and/or phase of an input optical waveform can be adjusted to yield an output optical waveform with a different temporal and/or spatial profile, relative to the input waveform.
The development of a commercial apparatus for computer-controlled, high-fidelity phase and amplitude pulse shaping has greatly facilitated the application of pulse shaping methods to diverse problems such as optical characterization of materials, time-division multiplexing in signaling systems, laser microscopy, and optical control of matter. Transformation of a single input optical pulse into one or more output pulses by manipulating the spectral properties of the input pulse in controlled fashion can be achieved through the use of a liquid crystal spatial light modulator array of the type manufactured by, for example, Cambridge Research & Instrumentation (Woburn, Mass.). Such a device includes two one-dimensional liquid crystal spatial light modulators, each oriented in a plane transverse to the light propagation direction. Liquid crystal modulators are typically transmissive for optical wavelengths in the range 400-1600 nm, and can be refreshed at a rate of roughly 10-100 ms, affording a means of adjusting either the phase or, in combination with additional optics, the amplitude of an input pulse with each one-dimensional spatial light modulator. To shape both the amplitude and phase of an optical waveform, both one-dimensional spatial light modulators are typically aligned and operated together.
Shaped optical waveforms can be used to measure properties of samples.